<template>
  <section class="msite">
    <!--首页头部-->
    <header-top :title="address.name">
      <router-link class="header_search" slot="left" to="/search">
        <i class="iconfont iconsousuo"></i>
      </router-link>
      <router-link class="header_login" slot="right" :to="userInfo._id ? '/userInfo' : 'login'">
        <span class="header_login_text" v-if="!userInfo._id">登录|注册</span>
        <span class="header_login_text" v-else>
          <i class="iconfont iconwo"></i>
        </span>
      </router-link>
    </header-top>

    <!--首页导航-->
    <nav class="msite_nav">
      <div class="swiper-container" v-if="categorys.length">
        <div class="swiper-wrapper">
          <div class="swiper-slide" v-for="(categorys, index) in categorysArr" :key="index">
            <a href="javascript:" class="link_to_food" v-for="(category, index) in categorys" :key="index">
              <div class="food_container">
                <img :src="baseImageUrl + category.image_url">
              </div>
              <span>{{ category.title }}</span>
            </a>
          </div>
        </div>
        <!-- Add Pagination -->
        <div class="swiper-pagination"></div>
      </div>
      <img src="./images/msite_back.svg" alt="back" v-else>
    </nav>
    <!--首页附近商家-->
    <div class="msite_shop_list">
      <div class="shop_header">
        <i class="iconfont icon-xuanxiang"></i>
        <span class="shop_header_title">附近商家</span>
      </div>
      <shop-list></shop-list>
    </div>
  </section>
</template>

<script>
import Swiper from 'swiper'
import 'swiper/swiper.min.css'

import HeaderTop from '../../components/HeaderTop/HeaderTop.vue'
import ShopList from '../../components/ShopList/ShopList.vue'

import { mapState, mapActions } from 'vuex'

export default {
  name: 'MSite',
  components: {
    HeaderTop,
    ShopList
  },
  data () {
    return {
      baseImageUrl: 'https://fuss10.elemecdn.com'
    }
  },
  mounted () {
    this.$store.dispatch('getAddress')
    this.$store.dispatch('getCategorys')
    this.$store.dispatch('getShops')
  },
  watch: {
    // watch监听，在categories中有数组了，有数据了，在异步更新页面之前执行
    categorys (val) {
      // 界面更新就立即创建Swiper对象，数据修改以后，就会马上执行
      this.$nextTick(() => {
        // 一旦完成界面更新，就会立即调用
        // 创建一个 Swiper 实例对象，来实现轮播
        new Swiper('.swiper-container', {
          loop: true, // 循环轮播
          // 添加分页器
          pagination: { 
            el: '.swiper-pagination'
          }
        })
      })
    }
  },
  // methods: {
  //   ...mapActions(['getAddress'])
  // },
  computed: {
    ...mapState(['address', 'categorys', 'userInfo']),
    // 根据categories一维数组生成一个二维数组，小数组的元素个数最大是8
    categorysArr () {
      // 获取分类数据
      const {categorys} = this
      // 空的二维数组
      const arr = []
      // 空的小数组，最大长度为8，每页显示8个
      let minArr = []
      // 遍历 categories
      categorys.forEach(c => {
        // 如果当前小数组已经满了，创建一个新的
        if (minArr.length === 8) {
          minArr = []
        }
         // 如果minArr是空的，将小数组保存到大数组中
        if (minArr.length === 0) {
          arr.push(minArr)
        }
        // 将当前的分类保存到小数组中去
        minArr.push(c)
      })
      return arr
    }
  }
}
</script>

<style lang="stylus" scoped>
    @import '../../common/stylus/mixins.styl'
    .msite  //首页
        width 100%
        .msite_nav
            bottom-border-1px(#e4e4e4)
            margin-top 45px
            height 200px
            background #fff
            .swiper-container
                width 100%
                height 100%
                .swiper-wrapper
                    width 100%
                    height 100%
                    .swiper-slide
                        display flex
                        justify-content center
                        align-items flex-start
                        flex-wrap wrap
                        .link_to_food
                            width 25%
                            .food_container
                                display block
                                width 100%
                                text-align center
                                padding-bottom 10px
                                font-size 0
                                img
                                    display inline-block
                                    width 50px
                                    height 50px
                            span
                                display block
                                width 100%
                                text-align center
                                font-size 13px
                                color #666
                .swiper-pagination
                    >span.swiper-pagination-bullet-active
                        background #02a774
        .msite_shop_list
            top-border-1px(#e4e4e4)
            margin-top 10px
            background #fff
            .shop_header
                padding 10px 10px 0
                .shop_icon
                    margin-left 5px
                    color #999
                .shop_header_title
                    color #999
                    font-size 14px
                    line-height 20px
</style>